a) Field of the Invention
The invention is directed to a device for transporting objects to a destination with at least one transfer mechanism for transferring the objects between the device and a receiving element for receiving the objects at the destination.
Such devices can be used mainly in semiconductor fabricating plants and by manufacturers for outfitting such fabricating plants.
b) Description of the Related Art
In semiconductor fabricating plants, it is customary for the substrates that are to be processed to be transported in open or closed containers between various locations and various processing devices by means of transport devices which are especially constructed for this purpose. In so doing, the handling of the containers during the required loading and unloading processes should be effected in an ergonomic manner for the operators. This is particularly important as the size of the substrate to be processed increases and accordingly as the size and weight of the containers increase.
Known simple transport cars have a simple storage capability for the containers and require that the loading and unloading be performed by the operator.
Automatically controlled vehicles require no input on the part of the operator, since these vehicles can move independently by means of their electronic equipment and corresponding auxiliary systems.
U.S. Pat. No. 5,570,990 describes a mobile loading device in the form of a cart with a swivelable transport arm having a plurality of members which are pivotally connected with one another by means of joints. The transport arm is fastened at the upper end of a vertically adjustable shaft. The swivelable transport arm serves to transport SMIF containers to a semiconductor processing station and back to the cart. To this end, the containers are grasped by a gripper and set down on the depositing space in the semiconductor processing station by a swiveling movement. The return transport is effected in the reverse manner. The processes are controlled and monitored by communicating means for communication between the semiconductor processing station and the cart.
While the operator must carry out the movements with the transport arm in the x-y plane by rotating the joints between the members of the transport arm without additional support, a motor-driven auxiliary device is provided for movements of the transport arm in the z direction in order to facilitate handling of heavy objects.
It is disadvantageous that separate operating processes are required for different transport movement directions. This makes the work sequence as well as the construction of the transport device more complicated and accordingly more costly.
It is especially important to provide a solution which is as simple as possible when using a transport system as an interim solution for an automatic system because the containers to be transported overstep permissible ergonomic boundaries. Manually operated transport systems are required precisely in the early and middle construction phases in semiconductor fabricating plants in order to optimize outfitting and work sequences. However, such interim solutions rule out the use of automatic systems with complicated and expensive electronics and sensor systems for cost reasons.